Deleting old email addresses from Gmail contacts
When you send an email from Google Gmail it will remember the recipient’s email address automatically. When you next compose an email Google will suggest previously used addresses so that you don’t need to remember the full address. This is handy because you don’t need to manually add new addresses to your contacts to take advantage of the autocomplete suggestions.
This can, however, cause problems further down the track when someone changes their email address or when you want to remove an incorrect address that was added as the result of a typo. Google will continue suggesting incorrect or invalid addresses until you manually remove them.
Here is a brief tutorial of that process.
To remove an address that is no longer valid start typing the address in a new email composition window. Click on the address once it is suggested.
Now click and hover over the address until the information box appears. Click on “Contact info”.
Now select “Delete contact” from the “More” menu.
If you wish to remove or update an email address belonging to someone who you want to keep in your contacts list: Start typing the obsolete address in a new email composition window and click on it once it is suggested.
Click and hover over the address until the information box appears. Click on “Contact info”.
Click on the obsolete address and then click on the trash icon next to it to delete it.
You can prevent Google from automatically remembering every address you send email to by clicking on the gear icon in the top-right of the screen, and then “Settings” from the drop-menu.
Select “I’ll add contacts myself” from the “General” tab. Now Google will only suggest addresses you have manually added to your contacts list or addresses that were automatically added before you changed this setting.